Heavy metals is a controversial and ambiguous term[2] formetallic elements with relatively highdensities,atomic weights, oratomic numbers. The criteria used, and whethermetalloids are included, vary depending on the author and context and it has been argued that the term "heavy metal" should be avoided.[3][4] A heavy metal may be defined on the basis of density, atomic number orchemical behaviour. More specific definitions have been published, none of which have been widely accepted. The definitions surveyed in this article encompass up to 96 out of the 118 knownchemical elements; onlymercury,lead andbismuth meet all of them. Despite this lack of agreement, the term (plural or singular) is widely used in science. A density of more than 5 g/cm3 is sometimes quoted as a commonly used criterion and is used in the body of this article.
Physical and chemical characterisations of heavy metals need to be treated with caution, as the metals involved are not always consistently defined. As well as being relatively dense, heavy metals tend to be lessreactive than lighter metals and have far fewersolublesulfides andhydroxides. While it is relatively easy to distinguish a heavy metal such astungsten from a lighter metal such assodium, a few heavy metals, such as zinc, mercury, and lead, have some of the characteristics of lighter metals; and lighter metals such asberyllium,scandium, and titanium, have some of the characteristics of heavier metals.
TheInternational Union of Pure and Applied Chemistry (IUPAC), which standardizes nomenclature, says "the termheavy metals is both meaningless and misleading".[2] The IUPAC report focuses on the legal and toxicological implications of describing "heavy metals" as toxins when there is no scientific evidence to support a connection. The density implied by the adjective "heavy" has almost no biological consequences and pure metals are rarely the biologically active substance.[5]This characterization has been echoed by numerous reviews.[6][7][8] The most widely used toxicology textbook,Casarett and Doull’s Toxicology[9] uses "toxic metal", not "heavy metal".[5] Nevertheless, there are scientific and science related articles which continue to use "heavy metal" as a term for toxic substances.[10][11] To be an acceptable term in scientific papers, a strict definition has been encouraged.[12]
Even in applications other than toxicity, there no widely agreed criterion-based definition of a heavy metal. Reviews have recommended that it not be used.[10][13] Different meanings may be attached to the term, depending on the context. For example, a heavy metal may be defined on the basis ofdensity,[14] the distinguishing criterion might beatomic number[15] or chemical behaviour.[16]
Density criteria range from above 3.5 g/cm3 to above 7 g/cm3.[17] Atomic weight definitions can range from greater thansodium (atomic weight 22.98);[17] greater than 40 (excludings- andf-block metals, hence starting withscandium);[18] or more than 200, i.e. frommercury onwards.[19] Atomic numbers are sometimes capped at 92 (uranium).[20] Definitions based on atomic number have been criticised for including metals with low densities. For example,rubidium ingroup (column) 1 of theperiodic table has an atomic number of 37 but a density of only 1.532 g/cm3, which is below the threshold figure used by other authors.[21] The same problem may occur with definitions which are based on atomic weight.[22]
This table shows the number of heavy metal criteria met by each metal, out of the ten criteria listed in this section i.e. two based ondensity, three onatomic weight, two onatomic number, and three on chemical behaviour.[n 1] It illustrates the lack of agreement surrounding the concept, with the possible exception ofmercury,lead andbismuth.
A different chemistry-based approach advocates replacing the term "heavy metal" with two groups of metals and a gray area. Class A metal ions preferoxygen donors; class B ions prefernitrogen orsulfur donors; and borderline or ambivalent ions show either class A or B characteristics, depending on the circumstances.[32] The distinction between the class A metals and the other two categories is sharp. The class A and class B terminology is analogous to the"hard acid" and "soft base" terminology sometimes used to refer to the behaviour of metal ions in inorganic systems.[33] The system groups the elements by where is the metal ionelectronegativity and is itsionic radius. This index gauges the importance ofcovalent interactions vsionic interactions for a given metal ion.[34] This scheme has been applied to analyze biologically active metals in sea water for example,[12] but it has not been widely adopted.[35]
In 1817, the German chemistLeopold Gmelin divided the elements into nonmetals, light metals, and heavy metals.[37] Light metals had densities of 0.860–5.0 g/cm3; heavy metals 5.308–22.000.[38] The term heavy metal is sometimes used interchangeably with the termheavy element. For example, in discussing the history ofnuclear chemistry, Magee[39] notes that the actinides were once thought to represent a new heavy element transition group whereasSeaborg and co-workers "favoured ... a heavy metalrare-earth like series ...".
A few non-essential heavy metals have been observed to have biological effects.Gallium, germanium (a metalloid), indium, and most lanthanides can stimulate metabolism, and titanium promotes growth in plants[52] (though it is not always considered a heavy metal).
Heavy metals are often assumed to be highly toxic or damaging to the environment.[53] Some are, while certain others are toxic only if taken in excess or encountered in certain forms. Inhalation of certain metals, either as fine dust or most commonly as fumes, can also result in a condition calledmetal fume fever.
Chromium, arsenic, cadmium, mercury, and lead have the greatest potential to cause harm on account of their extensive use, thetoxicity of some of their combined or elemental forms, and their widespread distribution in the environment.[54]Hexavalent chromium, for example, is highly toxic[citation needed] as are mercury vapour and many mercury compounds.[55] These five elements have a strong affinity for sulfur; in the human body they usually bind, viathiol groups (–SH), toenzymes responsible for controlling the speed of metabolic reactions. The resulting sulfur-metal bonds inhibit the proper functioning of the enzymes involved; human health deteriorates, sometimes fatally.[56] Chromium (in its hexavalent form) and arsenic arecarcinogens; cadmium causes adegenerative bone disease; and mercury and lead damage thecentral nervous system.[citation needed]
Lead is the most prevalent heavy metal contaminant.[57] Levels in the aquatic environments of industrialised societies have been estimated to be two to three times those of pre-industrial levels.[58] As a component oftetraethyl lead,(CH 3CH 2) 4Pb, it was used extensively ingasoline from the 1930s until the 1970s.[59] Although the use of leaded gasoline was largely phased out in North America by 1996, soils next to roads built before this time retain high lead concentrations.[60] Later research demonstrated a statistically significant correlation between the usage rate of leaded gasoline and violent crime in the United States; taking into account a 22-year time lag (for the average age of violent criminals), the violent crime curve virtually tracked the lead exposure curve.[61]
Other heavy metals noted for their potentially hazardous nature, usually as toxic environmental pollutants, include manganese (central nervous system damage);[62] cobalt andnickel (carcinogens);[63] copper,[64] zinc,[65] selenium[66] andsilver[67] (endocrine disruption,congenital disorders, or general toxic effects in fish, plants, birds, or other aquatic organisms); tin, asorganotin (central nervous system damage);[68] antimony (a suspected carcinogen);[69] andthallium (central nervous system damage).[64][n 9]
A few other non-essential heavy metals have one or more toxic forms. Kidney failure and fatalities have been recorded arising from the ingestion of germanium dietary supplements (~15 to 300 g in total consumed over a period of two months to three years).[64] Exposure toosmium tetroxide (OsO4) may cause permanent eye damage and can lead to respiratory failure[72] and death.[73] Indium salts are toxic if more than few milligrams are ingested and will affect the kidneys, liver, and heart.[74]Cisplatin (PtCl2(NH3)2), an important drug used tokill cancer cells, is also a kidney and nerve poison.[64]Bismuth compounds can cause liver damage if taken in excess; insoluble uranium compounds, as well as the dangerousradiation they emit, can cause permanent kidney damage.[75]
Heavy metals left of the dividing line occur (or are sourced) mainly aslithophiles; those to the right, aschalcophiles except gold (asiderophile) and tin (a lithophile).
Heavy metals up to thevicinity of iron (in the periodic table) are largely made viastellar nucleosynthesis. In this process, lighter elements from hydrogen tosilicon undergo successivefusion reactions inside stars, releasing light and heat and forming heavier elements with higher atomic numbers.[92]
Heavier heavy metals are not usually formed this way since fusion reactions involving such nuclei would consume rather than release energy.[93] Rather, they are largely synthesised (from elements with a lower atomic number) byneutron capture, with the two main modes of this repetitive capture being thes-process and ther-process. In the s-process ("s" stands for "slow"), singular captures are separated by years or decades, allowing the less stable nuclei tobeta decay,[94] while in the r-process ("rapid"), captures happen faster than nuclei can decay. Therefore, the s-process takes a more or less clear path: for example, stable cadmium-110 nuclei are successively bombarded by free neutrons inside a star until they form cadmium-115 nuclei which are unstable and decay to form indium-115 (which is nearly stable, with a half-life30,000 times the age of the universe). These nuclei capture neutrons and form indium-116, which is unstable, and decays to form tin-116, and so on.[92][95][n 11] In contrast, there is no such path in the r-process. The s-process stops at bismuth due to the short half-lives of the next two elements, polonium and astatine, which decay to bismuth or lead. The r-process is so fast it can skip this zone of instability and go on to create heavier elements such asthorium and uranium.[97]
Heavy metals condense in planets as a result of stellar evolution and destruction processes. Stars lose much of their mass when it isejected late in their lifetimes, and sometimes thereafter as a result of aneutron star merger,[98][n 12] thereby increasing the abundance of elements heavier than helium in theinterstellar medium. When gravitational attraction causes this matter to coalesce and collapse,new stars and planets are formed.[100]
The Earth's crust is made of approximately 5% of heavy metals by weight, with iron comprising 95% of this quantity. Light metals (~20%) and nonmetals (~75%) make up the other 95% of the crust.[89] Despite their overall scarcity, heavy metals can become concentrated in economically extractable quantities as a result ofmountain building,erosion, or othergeological processes.[101]
Heavy metals are found primarily aslithophiles (rock-loving) orchalcophiles (ore-loving). Lithophile heavy metals are mainly f-block elements and the more reactive of thed-block elements. They have a strong affinity for oxygen and mostly exist as relatively low densitysilicate minerals.[102] Chalcophile heavy metals are mainly the less reactive d-block elements, and period 4–6p-block metals and metalloids. They are usually found in (insoluble)sulfide minerals. Being denser than the lithophiles, hence sinking lower into the crust at the time of its solidification, the chalcophiles tend to be less abundant than the lithophiles.[103]
In contrast, gold is asiderophile, or iron-loving element. It does not readily form compounds with either oxygen or sulfur.[104] At the time of theEarth's formation, and as the mostnoble (inert) of metals, gold sank into thecore due to its tendency to form high-density metallic alloys. Consequently, it is a relatively rare metal.[105][failed verification] Some other (less) noble heavy metals—molybdenum,rhenium, theplatinum group metals (ruthenium, rhodium,palladium, osmium,iridium, and platinum), germanium, and tin—can be counted as siderophiles but only in terms of their primary occurrence in the Earth (core,mantle and crust), rather the crust. These metals otherwise occur in the crust, in small quantities, chiefly as chalcophiles (less so in theirnative form).[106][n 13]
Concentrations of heavy metals below the crust are generally higher, with most being found in the largely iron-silicon-nickel core.Platinum, for example, comprises approximately 1 part per billion of the crust whereas its concentration in the core is thought to be nearly 6,000 times higher.[107][108] Recent speculation suggests that uranium (and thorium) in the core may generate a substantial amount of the heat that drivesplate tectonics and (ultimately) sustains theEarth's magnetic field.[109][n 14]
Broadly speaking, and with some exceptions, lithophile heavy metals can be extracted from their ores byelectrical orchemical treatments, while chalcophile heavy metals are obtained byroasting their sulphide ores to yield the corresponding oxides, and then heating these to obtain the raw metals.[111][n 15] Radium occurs in quantities too small to be economically mined and is instead obtained from spentnuclear fuels.[114] The chalcophile platinum group metals (PGM) mainly occur in small (mixed) quantities with other chalcophile ores. The ores involved need to besmelted, roasted, and thenleached withsulfuric acid to produce a residue of PGM. This is chemically refined to obtain the individual metals in their pure forms.[115] Compared to other metals, PGM are expensive due to their scarcity[116] and high production costs.[117]
Gold, a siderophile, is most commonly recovered by dissolving the ores in which it is found in acyanide solution.[118] The gold forms a dicyanoaurate(I), for example: 2 Au +H2O +½ O2 + 4KCN → 2 K[Au(CN)2] + 2KOH. Zinc is added to the mix and, being morereactive than gold, displaces the gold: 2 K[Au(CN)2] + Zn → K2[Zn(CN)4] + 2 Au. The gold precipitates out of solution as a sludge, and is filtered off and melted.[119]
Some common uses of heavy metals depend on the general characteristics of metals such aselectrical conductivity andreflectivity or the general characteristics of heavy metals such as density, strength, and durability. Other uses depend on the characteristics of the specific element, such as their biological role as nutrients or poisons or some other specific atomic properties. Examples of such atomic properties include: partly filledd- orf- orbitals (in many of the transition, lanthanide, and actinide heavy metals) that enable the formation of coloured compounds;[120] the capacity of heavy metal ions (such as platinum,[121] cerium[122] or bismuth[123]) to exist in differentoxidation states and are used in catalysts;[124] strongexchange interactions in 3d or 4f orbitals (in iron, cobalt, and nickel, or the lanthanide heavy metals) that give rise to magnetic effects;[125] and high atomic numbers andelectron densities that underpin their nuclear science applications.[126] Typical uses of heavy metals can be broadly grouped into the following categories.[127]
In acello (example shown above) or aviola the C-string sometimes incorporatestungsten; its high density permits a smaller diameter string and improves responsiveness.[128]
Some uses of heavy metals, including in sport,mechanical engineering,military ordnance, andnuclear science, take advantage of their relatively high densities. Inunderwater diving, lead is used as aballast;[129] inhandicap horse racing each horse must carry a specified lead weight, based on factors including past performance, so as to equalize the chances of the various competitors.[130] Ingolf, tungsten,brass, or copper inserts infairwayclubs and irons lower the centre of gravity of the club making it easier to get the ball into the air;[131] and golf balls with tungsten cores are claimed to have better flight characteristics.[132] Infly fishing, sinking fly lines have aPVC coating embedded with tungsten powder, so that they sink at the required rate.[133] Intrack and field sport,steel balls used in thehammer throw andshot put events are filled with lead in order to attain the minimum weight required under international rules.[134] Tungsten was used in hammer throw balls at least up to 1980; the minimum size of the ball was increased in 1981 to eliminate the need for what was, at that time, an expensive metal (triple the cost of other hammers) not generally available in all countries.[135] Tungsten hammers were so dense that they penetrated too deeply into the turf.[136]
The higher the projectile density, the more effectively it can penetrate heavy armor plate ...Os,Ir,Pt, andRe ... are expensive ...U offers an appealing combination of high density, reasonable cost and high fracture toughness.
AM Russell and KL Lee Structure–property relations in nonferrous metals (2005, p. 16)
Thebiocidal effects ofsome heavy metals have been known since antiquity.[150] Platinum, osmium, copper, ruthenium, and other heavy metals, including arsenic, are used in anti-cancer treatments, or have shown potential.[151] Antimony (anti-protozoal), bismuth (anti-ulcer), gold (anti-arthritic), and iron (anti-malarial) are also important in medicine.[152] Copper, zinc, silver, gold, or mercury are used inantiseptic formulations;[153] small amounts of some heavy metals are used to control algal growth in, for example,cooling towers.[154] Depending on their intended use as fertilisers or biocides,agrochemicals may contain heavy metals such as chromium, cobalt, nickel, copper, zinc, arsenic, cadmium, mercury, or lead.[155]
Neodymium sulfate (Nd2(SO4)3), used to colour glassware[158]
The colours ofglass,ceramic glazes,paints,pigments, andplastics are commonly produced by the inclusion of heavy metals (or their compounds) such as chromium, manganese, cobalt, copper, zinc,zirconium, molybdenum, silver, tin,praseodymium,neodymium,erbium, tungsten, iridium, gold, lead, or uranium.[159]Tattoo inks may contain heavy metals, such as chromium, cobalt, nickel, and copper.[160] The high reflectivity of some heavy metals is important in the construction ofmirrors, including precisionastronomical instruments. Headlight reflectors rely on the excellent reflectivity of a thin film of rhodium.[161]
Heavy metals or their compounds can be found inelectronic components,electrodes, andwiring andsolar panels. Molybdenum powder is used incircuit board inks.[162] Home electrical systems, for the most part, are wired with copper wire for its good conducting properties.[163] Silver and gold are used in electrical and electronic devices, particularly in contactswitches, as a result of their high electrical conductivity and capacity to resist or minimise the formation of impurities on their surfaces.[164] Heavy metals have been used in batteries for over 200 years, at least sinceVolta invented his copper and silvervoltaic pile in 1800.[165]
Magnets are often made of heavy metals such as manganese, iron, cobalt, nickel, niobium, bismuth, praseodymium, neodymium, gadolinium, anddysprosium. Neodymium magnets are the strongest type ofpermanent magnet commercially available. They are key components of, for example, car door locks,starter motors,fuel pumps, andpower windows.[166]
Niche uses of heavy metals with high atomic numbers occur indiagnostic imaging,electron microscopy, and nuclear science. In diagnostic imaging, heavy metals such as cobalt or tungsten make up the anode materials found inx-ray tubes.[171] In electron microscopy, heavy metals such as lead, gold, palladium, platinum, or uranium have been used in the past to make conductive coatings and to introduce electron density into biological specimens bystaining,negative staining, orvacuum deposition.[172] In nuclear science, nuclei of heavy metals such as chromium, iron, or zinc are sometimes fired at other heavy metal targets to producesuperheavy elements;[173] heavy metals are also employed asspallation targets for the production ofneutrons[174] or isotopes of non-primordial elements such as astatine (using lead, bismuth, thorium, or uranium in the latter case).[175]
^ Criteria used weredensity:[17] (1) above 3.5 g/cm3; (2) above 7 g/cm3;atomic weight: (3) > 22.98;[17] (4) > 40 (excludings- andf-block metals);[18] (5) > 200;[19]atomic number: (6) > 20; (7) 21–92;[20]chemical behaviour: (8) United States Pharmacopeia;[23][24][25] (9) Hawkes' periodic table-based definition (excluding thelanthanides andactinides);[16] and (10) Nieboer and Richardson's biochemical classifications.[26] Densities of the elements are mainly from Emsley.[27] Predicted densities have been used forAt,Fr andFm–Ts.[28] Indicative densities were derived forFm,Md,No andLr based on their atomic weights, estimatedmetallic radii,[29] and predictedclose-packed crystalline structures.[30] Atomic weights are from Emsley,[27] inside back cover
^Metalloids were, however, excluded from Hawkes' periodic table-based definition given he noted it was "not necessary to decide whether semimetals [i.e. metalloids] should be included as heavy metals."[16]
^Lead, acumulative poison, has a relatively high abundance due to its extensive historical use and human-caused discharge into the environment.[42]
^Encompassing 45 heavy metals occurring in quantities of less than 10 mg each, including As (7 mg), Mo (5), Co (1.5), and Cr (1.4)[45]
^Of the elements commonly recognised as metalloids, B and Si were counted as nonmetals; Ge, As, Sb, and Te as heavy metals.
^Ni, Cu, Zn, Se, Ag and Sb appear in the United States Government'sToxic Pollutant List;[70] Mn, Co, and Sn are listed in the Australian Government'sNational Pollutant Inventory.[71]
^Trace elements having an abundancemuch less than the one part per trillion ofRa andPa (namelyTc,Pm,Po,At,Ac,Np, andPu) are not shown. Abundances are from Lide[89] and Emsley;[90] occurrence types are from McQueen.[91]
^The ejection of matter when two neutron stars collide is attributed to the interaction of theirtidal forces, possible crustal disruption, and shock heating (which is what happens if you floor the accelerator in a car when the engine is cold).[99]
^Iron, cobalt, nickel, germanium and tin are also siderophiles from a whole of Earth perspective.[91]
^Heat escaping from the inner solid core is believed to generate motion in the outer core, which is made of liquid iron alloys. The motion of this liquid generates electrical currents which give rise to a magnetic field.[110]
^Heavy metals that occur naturally in quantities too small to be economically mined (Tc, Pm, Po, At, Ac, Np and Pu) are instead produced byartificial transmutation.[112] The latter method is also used to produce heavy metals from americium onwards.[113]
^Electrons impacting the tungsten anode generate X-rays;[169] rhenium gives tungsten better resistance to thermal shock;[170] molybdenum and graphite act as heat sinks. Molybdenum also has a density nearly half that of tungsten thereby reducing the weight of the anode.[168]
^Namla, Djadjiti; Mangse, George; Koleoso, Peter O.; Ogbaga, Chukwuma C.; Nwagbara, Onyinye F. (2022). "Assessment of Heavy Metal Concentrations of Municipal Open-Air Dumpsite: A Case Study of Gosa Dumpsite, Abuja".Innovations and Interdisciplinary Solutions for Underserved Areas. Lecture Notes of the Institute for Computer Sciences, Social Informatics and Telecommunications Engineering. Vol. 449. pp. 165–174.doi:10.1007/978-3-031-23116-2_13.ISBN978-3-031-23115-5.
Ahrland S.,Liljenzin J. O. & Rydberg J. 1973, "Solution chemistry," in J. C. Bailar &A. F. Trotman-Dickenson (eds),Comprehensive Inorganic Chemistry, vol. 5, The Actinides,Pergamon Press, Oxford.
Albutt M. & Dell R. 1963,The nitrites and sulphides of uranium, thorium and plutonium: A review of present knowledge, UK Atomic Energy Authority Research Group,Harwell, Berkshire.
Alves A. K., Berutti, F. A. & Sánche, F. A. L. 2012, "Nanomaterials and catalysis", in C. P. Bergmann & M. J. de Andrade (ads),Nanonstructured Materials for Engineering Applications, Springer-Verlag, Berlin,ISBN978-3-642-19130-5.
Amasawa E., Yi Teah H., Yu Ting Khew, J., Ikeda I. & Onuki M. 2016, "Drawing Lessons from the Minamata Incident for the General Public: Exercise on Resilience, Minamata Unit AY2014", in M. Esteban, T. Akiyama, C. Chen, I. Ikea, T. Mino (eds),Sustainability Science: Field Methods and Exercises, Springer International, Switzerland, pp. 93–116,doi:10.1007/978-3-319-32930-7_5ISBN978-3-319-32929-1.
Ariel E., Barta J. & Brandon D. 1973, "Preparation and properties of heavy metals",Powder Metallurgy International, vol. 5, no. 3, pp. 126–129.
Bánfalvi G. 2011, "Heavy metals, trace elements and their cellular effects", in G. Bánfalvi (ed.),Cellular Effects of Heavy Metals,Springer, Dordrecht, pp. 3–28,ISBN978-94-007-0427-5.
Baranoff E. 2015, "First-row transition metal complexes for the conversion of light into electricity and electricity into light", in W-Y Wong (ed.),Organometallics and Related Molecules for Energy Conversion, Springer, Heidelberg, pp. 61–90,ISBN978-3-662-46053-5.
Berea E., Rodriguez-lbelo M. & Navarro J. A. R. 2016, "Platinum Group Metal—Organic frameworks" in S. Kaskel (ed.),The Chemistry of Metal-Organic Frameworks: Synthesis, Characterisation, and Applications, vol. 2, Wiley-VCH Weinheim, pp. 203–230,ISBN978-3-527-33874-0.
Berger A. J. & Bruning N. 1979,Lady Luck's Companion: How to Play ... How to Enjoy ... How to Bet ... How to Win, Harper & Row, New York,ISBN978-0-06-014696-2.
Berry L. G. & Mason B. 1959,Mineralogy: Concepts, Descriptions, Determinations, W. H. Freeman and Company, San Francisco.
Biddle H. C. & Bush G. L 1949,Chemistry Today,Rand McNally, Chicago.
Bonetti A., Leone R., Muggia F. & Howell S. B. (eds) 2009,Platinum and Other Heavy Metal Compounds in Cancer Chemotherapy: Molecular Mechanisms and Clinical Applications,Humana Press, New York,ISBN978-1-60327-458-6.
Booth H. S. 1957,Inorganic Syntheses, vol. 5, McGraw-Hill, New York.
Bradl H. E. 2005, "Sources and origins of heavy metals", in Bradl H. E. (ed.),Heavy Metals in the Environment: Origin, Interaction and Remediation, Elsevier, Amsterdam,ISBN978-0-12-088381-3.
Brephohl E. &McCreight T. (ed) 2001,The Theory and Practice of Goldsmithing, C. Lewton-Brain trans., Brynmorgen Press, Portland, Maine,ISBN978-0-9615984-9-5.
Brown I. 1987, "Astatine: Its organonuclear chemistry and biomedical applications," in H. J. Emeléus & A. G. Sharpe (eds),Advances in Inorganic Chemistry, vol. 31,Academic Press, Orlando, pp. 43–88,ISBN978-0-12-023631-2.
Bryson R. M. & Hammond C. 2005, "Generic methodologies for nanotechnology: Characterisation"', in R. Kelsall, I. W. Hamley & M. Geoghegan,Nanoscale Science and Technology, John Wiley & Sons, Chichester, pp. 56–129,ISBN978-0-470-85086-2.
Burkett B. 2010,Sport Mechanics for Coaches, 3rd ed., Human Kinetics, Champaign, Illinois,ISBN978-0-7360-8359-1.
Casey C. 1993, "Restructuring work: New work and new workers in post-industrial production", in R. P. Coulter & I. F. Goodson (eds),Rethinking Vocationalism: Whose Work/life is it?, Our Schools/Our Selves Education Foundation, Toronto,ISBN978-0-921908-15-9.
Chakhmouradian A.R., Smith M. P. & Kynicky J. 2015, "From "strategic" tungsten to "green" neodymium: A century of critical metals at a glance",Ore Geology Reviews, vol. 64, January, pp. 455–458,doi:10.1016/j.oregeorev.2014.06.008.
Chambers E. 1743, "Metal", inCyclopedia: Or an Universal Dictionary of Arts and Sciences (etc.), vol. 2, D. Midwinter, London.
Chen J. & Huang K. 2006, "A new technique for extraction of platinum group metals by pressure cyanidation",Hydrometallurgy, vol. 82, nos. 3–4, pp. 164–171,doi:10.1016/j.hydromet.2006.03.041.
Choptuik M. W., Lehner L. & Pretorias F. 2015, "Probing strong-field gravity through numerical simulation", inA. Ashtekar,B. K. Berger, J. Isenberg & M. MacCallum (eds),General Relativity and Gravitation: A Centennial Perspective, Cambridge University Press, Cambridge,ISBN978-1-107-03731-1.
Clugston M & Flemming R 2000,Advanced Chemistry, Oxford University, Oxford,ISBN978-0-19-914633-8.
Cole M., Lindeque P., Halsband C. & Galloway T. S. 2011, "Microplastics as contaminants in the marine environment: A review",Marine Pollution Bulletin, vol. 62, no. 12, pp. 2588–2597,doi:10.1016/j.marpolbul.2011.09.025.
Cole S. E. & Stuart K. R. 2000, "Nuclear and cortical histology forbrightfield microscopy", in D. J. Asai & J. D. Forney (eds),Methods in Cell Biology, vol. 62, Academic Press, San Diego, pp. 313–322,ISBN978-0-12-544164-3.
Cotton S. A. 1997,Chemistry of Precious Metals, Blackie Academic & Professional, London,ISBN978-94-010-7154-3.
Crundwell F. K., Moats M. S., Ramachandran V., Robinson T. G. & Davenport W. G. 2011,Extractive Metallurgy of Nickel, Cobalt and Platinum Group Metals, Elsevier, Kidlington, Oxford,ISBN978-0-08-096809-4.
Cui X-Y., Li S-W., Zhang S-J., Fan Y-Y., Ma L. Q. 2015, "Toxic metals in children's toys and jewelry: Coupling bioaccessibility with risk assessment",Environmental Pollution, vol. 200, pp. 77–84,doi:10.1016/j.envpol.2015.01.035.
Dapena J. & Teves M. A. 1982, "Influence of the diameter of the hammer head on the distance of a hammer throw",Research Quarterly for Exercise and Sport, vol. 53, no. 1, pp. 78–81,doi:10.1080/02701367.1982.10605229.
De Zuane J. 1997,Handbook of Drinking Water Quality, 2nd ed., John Wiley & Sons, New York,ISBN978-0-471-28789-6.
Deschlag J. O. 2011, "Nuclear fission", in A. Vértes, S. Nagy, Z. Klencsár, R. G. Lovas, F. Rösch (eds),Handbook of Nuclear Chemistry, 2nd ed.,Springer Science+Business Media, Dordrecht, pp. 223–280,ISBN978-1-4419-0719-6.
Desoize B. 2004, "Metals and metal compounds in cancer treatment",Anticancer Research, vol. 24, no. 3a, pp. 1529–1544,PMID15274320.
Dev N. 2008, 'Modelling Selenium Fate and Transport in Great Salt Lake Wetlands', PhD dissertation, University of Utah,ProQuest, Ann Arbor, Michigan,ISBN978-0-549-86542-1.
Edelstein N. M., Fuger J., Katz J. L. & Morss L. R. 2010, "Summary and comparison of properties of the actinde and transactinide elements," in L. R. Morss, N. M. Edelstein & J. Fuger (eds),The Chemistry of the Actinide and Transactinide Elements, 4th ed., vol. 1–6,Springer, Dordrecht, pp. 1753–1835,ISBN978-94-007-0210-3.
Gschneidner Jr., K. A. 1975,Inorganic compounds, in C. T. Horowitz (ed.),Scandium: Its Occurrence, Chemistry, Physics, Metallurgy, Biology and Technology,Academic Press, London, pp. 152–251,ISBN978-0-12-355850-3.
Guandalini G. S., Zhang L., Fornero E., Centeno J. A., Mokashi V. P., Ortiz P. A., Stockelman M. D., Osterburg A. R. & Chapman G. G. 2011, "Tissue distribution of tungsten in mice following oral exposure to sodium tungstate,"Chemical Research in Toxicology, vol. 24, no. 4, pp 488–493,doi:10.1021/tx200011k.
Guney M. & Zagury G. J. 2012, "Heavy metals in toys and low-cost jewelry: Critical review of U.S. and Canadian legislations and recommendations for testing",Environmental Science & Technology, vol. 48, pp. 1238–1246,doi:10.1021/es4036122.
Harvey P. J., Handley H. K. & Taylor M. P. 2015, "Identification of the sources of metal (lead) contamination in drinking waters in north-eastern Tasmania using lead isotopic compositions,"Environmental Science and Pollution Research, vol. 22, no. 16, pp. 12276–12288,doi:10.1007/s11356-015-4349-2PMID25895456.
Hawkes S. J. 1997, "What is a "heavy metal"?",Journal of Chemical Education, vol. 74, no. 11, p. 1374,doi:10.1021/ed074p1374.
Haynes W. M. 2015,CRC Handbook of Chemistry and Physics, 96th ed., CRC Press, Boca Raton, Florida,ISBN978-1-4822-6097-7.
Hendrickson D. J. 2916, "Effects of early experience on brain and body", in D. Alicata, N. N. Jacobs, A. Guerrero and M. Piasecki (eds),Problem-based Behavioural Science and Psychiatry 2nd ed., Springer, Cham, pp. 33–54,ISBN978-3-319-23669-8.
Herron N. 2000, "Cadmium compounds," inKirk-Othmer Encyclopedia of Chemical Technology, vol. 4, John Wiley & Sons, New York, pp. 507–523,ISBN978-0-471-23896-6.
Hoffman D. C., Lee D. M. & Pershina V. 2011, "Transactinide elements and future elements," in L. R. Morss, N. Edelstein, J. Fuger & J. J. Katz (eds),The Chemistry of the Actinide and Transactinide Elements, 4th ed., vol. 3, Springer, Dordrecht, pp. 1652–1752,ISBN978-94-007-0210-3.
Ikehata K., Jin Y., Maleky N. & Lin A. 2015, "Heavy metal pollution in water resources in China—Occurrence and public health implications", in S. K. Sharma (ed.),Heavy Metals in Water: Presence, Removal and Safety,Royal Society of Chemistry, Cambridge, pp. 141–167,ISBN978-1-84973-885-9.
International Antimony Association 2016,Antimony compounds, accessed 2 September 2016.
Iyengar G. V. 1998, "Reevaluation of the trace element content in Reference Man",Radiation Physics and Chemistry, vol. 51, nos 4–6, pp. 545–560,doi:10.1016/S0969-806X(97)00202-8
Jackson J. & Summitt J. 2006,The Modern Guide to Golf Clubmaking: The Principles and Techniques of Component Golf Club Assembly and Alteration, 5th ed., Hireko Trading Company, City of Industry, California,ISBN978-0-9619413-0-7.
Kolthoff I. M. & Elving P. J. FR 1964,Treatise on Analytical Chemistry, part II, vol. 6, Interscience Encyclopedia, New York,ISBN978-0-07-038685-3.
Korenman I. M. 1959, "Regularities in properties of thallium",Journal of General Chemistry of the USSR, English translation, Consultants Bureau, New York, vol. 29, no. 2, pp. 1366–90,ISSN0022-1279.
Kozin L. F. & Hansen S. C. 2013,Mercury Handbook: Chemistry, Applications and Environmental Impact,RSC Publishing, Cambridge,ISBN978-1-84973-409-7.
Kumar R., Srivastava P. K., Srivastava S. P. 1994, "Leaching of heavy metals (Cr, Fe, and Ni) from stainless steel utensils in food simulates and food materials",Bulletin of Environmental Contamination and Toxicology, vol. 53, no. 2,doi:10.1007/BF00192942, pp. 259–266.
Landis W., Sofield R. & Yu M-H. 2010,Introduction to Environmental Toxicology: Molecular Substructures to Ecological Landscapes, 4th ed., CRC Press, Boca Raton, Florida,ISBN978-1-4398-0411-7.
Lane T. W., Saito M. A., George G. N., Pickering, I. J., Prince R. C. & Morel F. M. M. 2005, "Biochemistry: A cadmium enzyme from a marine diatom",Nature, vol. 435, no. 7038, p. 42,doi:10.1038/435042a.
Lemly A. D. 1997, "A teratogenic deformity index for evaluating impacts of selenium on fish populations",Ecotoxicology and Environmental Safety, vol. 37, no. 3, pp. 259–266,doi:10.1006/eesa.1997.1554.
Lide D. R. (ed.) 2004,CRC Handbook of Chemistry and Physics, 85th ed., CRC Press, Boca Raton, Florida,ISBN978-0-8493-0485-9.
Liens J. 2010, "Heavy metals as pollutants", in B. Warf (ed.),Encyclopaedia of Geography, Sage Publications, Thousand Oaks, California, pp. 1415–1418,ISBN978-1-4129-5697-0.
Litasov K. D. & Shatskiy A. F. 2016, "Composition of the Earth's core: A review",Russian Geology and Geophysics, vol. 57, no. 1, pp. 22–46,doi:10.1016/j.rgg.2016.01.003.
Love M. 1998,Phasing Out Lead from Gasoline: Worldwide Experience and Policy Implications, World Bank Technical Paper volume 397,The World Bank, Washington DC,ISBN0-8213-4157-X.
Lyman W. J. 1995, "Transport and transformation processes", inFundamentals of Aquatic Toxicology, G. M. Rand (ed.), Taylor & Francis, London, pp. 449–492,ISBN978-1-56032-090-6.
Macintyre J. E. 1994,Dictionary of inorganic compounds, supplement 2, Dictionary of Inorganic Compounds, vol. 7,Chapman & Hall, London,ISBN978-0-412-49100-9.
MacKay K. M., MacKay R. A. & Henderson W. 2002,Introduction to Modern Inorganic Chemistry, 6th ed., Nelson Thornes, Cheltenham,ISBN978-0-7487-6420-4.
Magee R. J. 1969,Steps to Atomic Power, Cheshire for La Trobe University, Melbourne.
Magill F. N. I (ed.) 1992,Magill's Survey of Science, Physical Science series, vol. 3, Salem Press, Pasadena,ISBN978-0-89356-621-0.
Martin M. H. & Coughtrey P. J. 1982,Biological Monitoring of Heavy Metal Pollution, Applied Science Publishers, London,ISBN978-0-85334-136-9.
Masters C. 1981,Homogenous Transition-metal Catalysis: A Gentle Art, Chapman and Hall, London,ISBN978-0-412-22110-1.
Matyi R. J. & Baboian R. 1986, "An X-ray Diffraction Analysis of the Patina of the Statue of Liberty",Powder Diffraction, vol. 1, no. 4, pp. 299–304,doi:10.1017/S0885715600011970.
McColm I. J. 1994,Dictionary of Ceramic Science and Engineering, 2nd ed., Springer Science+Business Media, New York,ISBN978-1-4419-3235-8.
McCurdy, Richard M. (1975).Qualities and quantities: preparation for college chemistry. New York: Harcourt Brace Jovanovich.ISBN978-0-15-574100-3.
McLemore V. T. (ed.) 2008,Basics of Metal Mining Influenced Water, vol. 1, Society for Mining, Metallurgy, and Exploration, Littleton, Colorado,ISBN978-0-87335-259-8.
McQueen K. G. 2009,Regolith geochemistry, in K. M. Scott & C. F. Pain (eds),Regolith Science,CSIRO Publishing, Collingwood, Victoria,ISBN978-0-643-09396-6.
Moore J. W. & Ramamoorthy S. 1984,Heavy Metals in Natural Waters: Applied Monitoring and Impact Assessment,Springer Verlag, New York,ISBN978-1-4612-9739-0.
Morstein J. H. 2005, "Fat Man", in E. A. Croddy & Y. Y. Wirtz (eds),Weapons of Mass Destruction: An Encyclopedia of Worldwide Policy, Technology, and History,ABC-CLIO, Santa Barbara, California,ISBN978-1-85109-495-0.
Moselle B. (ed.) 2005,2004 National Home Improvement Estimator, Craftsman Book Company, Carlsbad, California,ISBN978-1-57218-150-2.
Naja G. M. & Volesky B. 2009, "Toxicity and sources of Pb, Cd, Hg, Cr, As, and radionuclides", in L. K. Wang, J. P. Chen, Y. Hung & N. K. Shammas,Heavy Metals in the Environment, CRC Press, Boca Raton, Florida,ISBN978-1-4200-7316-4.
Nakbanpote W., Meesungneon O. & Prasad M. N. V. 2016, "Potential of ornamental plants for phytoremediation of heavy metals and income generation", in M. N. V. Prasad (ed.),Bioremediation and Bioeconomy,Elsevier, Amsterdam, pp. 179–218,ISBN978-0-12-802830-8.
Nathans M. W. 1963,Elementary Chemistry,Prentice Hall, Englewood Cliffs, New Jersey.
National Materials Advisory Board 1971,Trends in the Use of Depleted Uranium, National Academy of Sciences – National Academy of Engineering, Washington DC.
Nieboer E. & Richardson D. 1978, "Lichens and 'heavy metals' ",International Lichenology Newsletter, vol. 11, no. 1, pp. 1–3.
Nieboer E. & Richardson D. H. S. 1980, "The replacement of the nondescript term 'heavy metals' by a biologically and chemically significant classification of metal ions",Environmental Pollution Series B, Chemical and Physical, vol. 1, no. 1, pp. 3–26,doi:10.1016/0143-148X(80)90017-8.
Ohlendorf H. M. 2003, "Ecotoxicology of selenium", in D. J. Hoffman, B. A. Rattner, G. A. Burton &J. Cairns,Handbook of Ecotoxicology, 2nd ed.,Lewis Publishers, Boca Raton, pp. 466–491,ISBN978-1-56670-546-2.
Ondreička R., Kortus J. & Ginter E. 1971, "Aluminium, its absorption, distribution, and effects on phosphorus metabolism", in S. C. Skoryna & D. Waldron-Edward (eds),Intestinal Absorption of Metal Ions, Trace Elements and Radionuclides, Pergamon press, Oxford.
Ong K. L., Tan T. H. & Cheung W. L. 1997, "Potassium permanganate poisoning—a rare cause of fatal poisoning",Journal of Accident & Emergency Medicine, vol. 14, no. 1, pp. 43–45,PMC1342846.
Pan W. & Dai J. 2015, "ADS based on linear accelerators", in W. Chao & W. Chou (eds),Reviews of accelerator science and technology, vol. 8, Accelerator Applications in Energy and Security,World Scientific, Singapore, pp. 55–76,ISBN981-3108-89-4.
Perry J. & Vanderklein E. L.Water Quality: Management of a Natural Resource, Blackwell Science, Cambridge, MassachusettsISBN0-86542-469-1.
Pickering N. C. 1991,The Bowed String: Observations on the Design, Manufacture, Testing and Performance of Strings for Violins, Violas and Cellos, Amereon, Mattituck, New York.
Podosek F. A. 2011, "Noble gases", in H. D. Holland &K. K. Turekian (eds),Isotope Geochemistry: From the Treatise on Geochemistry, Elsevier, Amsterdam, pp. 467–492,ISBN978-0-08-096710-3.
Raghuram P., Soma Raju I. V. & Sriramulu J. 2010, "Heavy metals testing in active pharmaceutical ingredients: an alternate approach",Pharmazie, vol. 65, no. 1, pp. 15–18,doi:10.1691/ph.2010.9222.
Rand G. M., Wells P. G. & McCarty L. S. 1995, "Introduction to aquatic toxicology", in G. M. Rand (ed.),Fundamentals of Aquatic Toxicology: Effects, Environmental Fate and Risk Assessment, 2nd ed., Taylor & Francis, London, pp. 3–70,ISBN978-1-56032-090-6.
Rankin W. J. 2011,Minerals, Metals and Sustainability: Meeting Future Material Needs, CSIRO Publishing, Collingwood, Victoria,ISBN978-0-643-09726-1.
Rasic-Milutinovic Z. & Jovanovic D. 2013, "Toxic metals", in M. Ferrante, G. Oliveri Conti, Z. Rasic-Milutinovic & D. Jovanovic (eds),Health Effects of Metals and Related Substances in Drinking Water,IWA Publishing, London,ISBN978-1-68015-557-0.
Raymond R. 1984,Out of the Fiery Furnace: The Impact of Metals on the History of Mankind,Macmillan, South Melbourne,ISBN978-0-333-38024-6.
Rebhandl W., Milassin A., Brunner L., Steffan I., Benkö T., Hörmann M., Burschen J. 2007, "In vitro study of ingested coins: Leave them or retrieve them?",Journal of Paediatric Surgery, vol. 42, no. 10, pp. 1729–1734,doi:10.1016/j.jpedsurg.2007.05.031.
Rehder D. 2010,Chemistry in Space: From Interstellar Matter to the Origin of Life, Wiley-VCH, Weinheim,ISBN978-3-527-32689-1.
Renner H., Schlamp G., Kleinwächter I., Drost E., Lüchow H. M., Tews P., Panster P., Diehl M., Lang J., Kreuzer T., Knödler A., Starz K. A., Dermann K., Rothaut J., Drieselmann R., Peter C. & Schiele R. 2012, "Platinum Group Metals and compounds", in F. Ullmann (ed.),Ullmann's Encyclopedia of Industrial Chemistry, vol. 28, Wiley-VCH, Weinheim, pp. 317–388,doi:10.1002/14356007.a21_075.
Ridpath I. (ed.) 2012,Oxford Dictionary of Astronomy, 2nd ed. rev., Oxford University Press, New York,ISBN978-0-19-960905-5.
Rockhoff H. 2012,America's Economic Way of War: War and the US Economy from the Spanish–American War to the Persian Gulf War, Cambridge University Press, Cambridge,ISBN978-0-521-85940-0.
Roe J. & Roe M. 1992, "World's coinage uses 24 chemical elements",World Coinage News, vol. 19, no. 4, pp. 24–25; no. 5, pp. 18–19.
Russell A. M. & Lee K. L. 2005,Structure–Property Relations in Nonferrous Metals, John Wiley & Sons, Hoboken, New Jersey,ISBN978-0-471-64952-6.
Rusyniak D. E., Arroyo A., Acciani J., Froberg B., Kao L. & Furbee B. 2010, "Heavy metal poisoning: Management of intoxication and antidotes", in A. Luch (ed.),Molecular, Clinical and Environmental Toxicology, vol. 2, Birkhäuser Verlag, Basel, pp. 365–396,ISBN978-3-7643-8337-4.
Ryan J. 2012,Personal Financial Literacy, 2nd ed., South-Western, Mason, Ohio,ISBN978-0-8400-5829-4.
Samsonov G. V. (ed.) 1968,Handbook of the Physicochemical Properties of the Elements, IFI-Plenum, New York,ISBN978-1-4684-6066-7.
Scott R. M. 1989,Chemical Hazards in the Workplace, CRC Press, Boca Raton, Orlando,ISBN978-0-87371-134-0.
Scoullos M. (ed.), Vonkeman G. H., Thornton I. & Makuch Z. 2001,Mercury — Cadmium — Lead Handbook for Sustainable Heavy Metals Policy and Regulation,Kluwer Academic Publishers, Dordrecht,ISBN978-1-4020-0224-3.
Shaw B. P., Sahu S. K. & Mishra R. K. 1999, "Heavy metal induced oxidative damage in terrestrial plants", in M. N. V. Prased (ed.),Heavy Metal Stress in Plants: From Biomolecules to Ecosystems Springer-Verlag, Berlin,ISBN978-3-540-40131-5.
Sidgwick N. V. 1950,The Chemical Elements and their Compounds, vol. 1, Oxford University Press, London.
Silva R. J. 2010, "Fermium, mendelevium, nobelium, and lawrencium", in L. R. Morss, N. Edelstein & J. Fuger (eds),The Chemistry of the Actinide and Transactinide Elements, vol. 3, 4th ed., Springer, Dordrecht, pp. 1621–1651,ISBN978-94-007-0210-3.
Spolek G. 2007, "Design and materials in fly fishing", in A. Subic (ed.),Materials in Sports Equipment, Volume 2,Woodhead Publishing, Abington, Cambridge, pp. 225–247,ISBN978-1-84569-131-8.
Stankovic S. & Stankocic A. R. 2013, "Bioindicators of toxic metals", in E. Lichtfouse, J. Schwarzbauer, D. Robert 2013,Green materials for energy, products and depollution, Springer, Dordrecht,ISBN978-94-007-6835-2, pp. 151–228.
State Water Control Resources Board 1987,Toxic substances monitoring program, issue 79, part 20 of the Water Quality Monitoring Report, Sacramento, California.
Thorne P. C. L. & Roberts E. R. 1943,Fritz Ephraim Inorganic Chemistry, 4th ed., Gurney and Jackson, London.
Tisza M. 2001,Physical Metallurgy for Engineers, ASM International, Materials Park, Ohio,ISBN978-0-87170-725-3.
Tokar E. J., Boyd W. A., Freedman J. H. & Wales M. P. 2013, "Toxic effects of metals", in C. D. Klaassen (ed.),Casarett and Doull's Toxicology: the Basic Science of Poisons, 8th ed.,McGraw-Hill Medical, New York,ISBN978-0-07-176923-5, accessed 9 September 2016(subscription required).
Tomasik P. & Ratajewicz Z. 1985,Pyridine metal complexes, vol. 14, no. 6A, The Chemistry of Heterocyclic Compounds, John Wiley & Sons, New York,ISBN978-0-471-05073-5.
Topp N. E. 1965,The Chemistry of the Rare-earth Elements, Elsevier Publishing Company, Amsterdam.
Uden P. C. 2005, 'Speciation of Selenium,' in R. Cornelis, J. Caruso, H. Crews & K. Heumann (eds),Handbook of Elemental Speciation II: Species in the Environment, Food, Medicine and Occupational Health, John Wiley & Sons, Chichester, pp. 346–65,ISBN978-0-470-85598-0.
United States Environmental Protection Agency 1988,Ambient Aquatic Life Water Quality Criteria for Antimony (III), draft, Office of Research and Development, Environmental Research Laboratories, Washington.
Valkovic V. 1990, "Origin of trace element requirements by living matter", in B. Gruber & J. H. Yopp (eds),Symmetries in Science IV: Biological and biophysical systems, Plenum Press, New York, pp. 213–242,ISBN978-1-4612-7884-9.
Venugopal B. & Luckey T. D. 1978,Metal Toxicity in Mammals, vol. 2, Plenum Press, New York,ISBN978-0-306-37177-6.
Vernon R. E. 2013, "Which elements are metalloids",Journal of Chemical Education, vol. 90, no. 12, pp. 1703–1707,doi:10.1021/ed3008457.
Volesky B. 1990,Biosorption of Heavy Metals, CRC Press, Boca Raton,ISBN978-0-8493-4917-1.
von Gleich A. 2013, "Outlines of a sustainable metals industry", in A. von Gleich, R. U. Ayres & S. Gößling-Reisemann (eds),Sustainable Metals Management, Springer, Dordrecht, pp. 3–40,ISBN978-1-4020-4007-8.
von Zeerleder A. 1949,Technology of Light Metals, Elsevier Publishing Company, New York.
Warth A. H. 1956,The Chemistry and Technology of Waxes, Reinhold Publishing Corporation, New York.
Weart S. R. 1983, "The discovery of nuclear fission and a nuclear physics paradigm", in W. Shea (ed.),Otto Hahn and the Rise of Nuclear Physics,D. Reidel Publishing Company, Dordrecht, pp. 91–133,ISBN978-90-277-1584-5.
Weber D. J. & Rutula W. A. 2001, "Use of metals as microbicides in preventing infections in healthcare", inDisinfection, Sterilization, and Preservation, 5th ed., S. S. Block (ed.),Lippincott, Williams & Wilkins, Philadelphia,ISBN978-0-683-30740-5.
Welter G. 1976,Cleaning and Preservation of Coins and Medals, S. J. Durst, New York,ISBN978-0-915262-03-8.
Wiberg N. 2001,Inorganic Chemistry, Academic Press, San Diego,ISBN978-0-12-352651-9.
Wijayawardena M. A. A., Megharaj M. & Naidu R. 2016, "Exposure, toxicity, health impacts and bioavailability of heavy metal mixtures", in D. L. Sparks,Advances in Agronomy, vol. 138, pp. 175–234, Academic Press, London,ISBN978-0-12-804774-3.
Wong M. Y., Hedley G. J., Xie G., Kölln L. S, Samuel I. D. W., Pertegaś A., Bolink H. J., Mosman-Colman, E., "Light-emitting electrochemical cells and solution-processed organic light-emitting diodes using small molecule organic thermally activated delayed fluorescence emitters",Chemistry of Materials, vol. 27, no. 19, pp. 6535–6542,doi:10.1021/acs.chemmater.5b03245.
Wulfsberg G. 2000,Inorganic Chemistry, University Science Books, Sausalito, California,ISBN978-1-891389-01-6.
Yadav J. S., Antony A., Subba Reddy, B. V. 2012, "Bismuth(III) salts as synthetic tools in organic transformations", in T. Ollevier (ed.),Bismuth-mediated Organic Reactions, Topics in Current Chemistry 311, Springer, Heidelberg,ISBN978-3-642-27238-7.
Yang D. J., Jolly W. L. & O'Keefe A. 1977, "Conversion of hydrous germanium(II) oxide to germynyl sesquioxide, (HGe)2O3",'Inorganic Chemistry, vol. 16, no. 11, pp. 2980–2982,doi:10.1021/ic50177a070.
Yousif N. 2007,Geochemistry of stream sediment from the state of Colorado using NURE data, ETD Collection for the University of Texas, El Paso,paper AAI3273991.
Ali H. & Khan E. 2017, "What are heavy metals? Long-standing controversy over the scientific use of the term 'heavy metals'—proposal of a comprehensive definition",Toxicological & Environmental Chemistry, pp. 1–25,doi:10.1080/02772248.2017.1413652. Suggests defining heavy metals as "naturally occurring metals having atomic number (Z) greater than 20 and an elemental density greater than 5 g cm−3".
Hübner R., Astin K. B. & Herbert R. J. H. 2010,"'Heavy metal'—time to move on from semantics to pragmatics?",Journal of Environmental Monitoring, vol. 12, pp. 1511–1514,doi:10.1039/C0EM00056F. Finds that, despite its lack of specificity, the term appears to have become part of the language of science.
Toxicity and biological role
Baird C. & Cann M. 2012,Environmental Chemistry, 5th ed., chapter 12, "Toxic heavy metals",W. H. Freeman and Company, New York,ISBN1-4292-7704-1. Discusses the use, toxicity, and distribution of Hg, Pb, Cd, As, and Cr.
Nieboer E. & Richardson D. H. S. 1980, "The replacement of the nondescript term 'heavy metals' by a biologically and chemically significant classification of metal ions",Environmental Pollution Series B, Chemical and Physical, vol. 1, no. 1, pp. 3–26,doi:10.1016/0143-148X(80)90017-8. A widely cited paper, focusing on the biological role of heavy metals.
Koehler C. S. W. 2001, "Heavy metal medicine",Chemistry Chronicles, American Chemical Society, accessed 11 July 2016
Morowitz N. 2006, "The heavy metals",Modern Marvels, season 12, episode 14,HistoryChannel.com
Öhrström L. 2014, "Tantalum oxide",Chemistry World, 24 September, accessed 4 October 2016. The author explains how tantalum(V) oxide banished brick-sized mobile phones. Also available as apodcast.
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